>— 1 


THE  UNIVERSITY 

OF  ILLINOIS 

LIBRARY 

630.7 
I16b 


cop-Z 


A6RICULTURAL 


ING 


I 


UNIVERSITY  OF  ILLINOIS 

Agricultural  Experiment  Station 


BULLETIN  NO.  242 


FLAG  SMUT  OF  WHEAT,  WITH  SPECIAL 

REFERENCE  TO  VARIETAL 

RESISTANCE 

IN   COOPERATION   WITH   OFFICE   OF   CEREAL   INVESTIGATIONS 
BUREAU  OF  PLANT  INDUSTRY,   U.   S.   DEPARTMENT   OF  AGRICULTURE 


BY  W.  H.  TISDALE,  G.  H.  DUNGAN,  AND 
C.  E.  LEIGHTY 


URBANA,  ILLINOIS,  APRIL,  1923 


ACKNOWLEDGMENT 

The  writers  wish  to  acknowledge  their  indebtedness  to 
the  following  persons:  Dr.  George  M.  Reed,  who  super- 
vised the  work  for  the  Office  of  Cereal  Investigations, 
U.  S.  Department  of  Agriculture,  during  its  earlier  stages ; 
Drs.  W.  L.  Burlison  and  H.  B.  Humphrey,  for  advice  and 
helpful  criticisms  of  the  manuscript;  Professor  J.  C. 
Hackleman,  for  advice  regarding  varieties;  the  Board  of 
Education  of  the  Granite  City  Community  High  School, 
Madison  county,  Illinois,  who  kindly  furnished  land  for 
the  experiment  plats;  Mr.  Louis  Soechtig,  who  prepared 
the  land  for  planting  and  who  has  cooperated  cheerfully  by 
increasing  certain  varieties  that  show  resistance  to  flag 
smut;  and  Miss  M.  A.  Griffiths  and  Mr.  F.  S.  Wolpert, 
for  assistance  in  the  work  as  it  was  in  progress. 


CONTENTS  OP  BULLETIN  No.  242 

PAGE 
SUMMARY 510 

INTRODUCTION 511 

HISTORY  AND  PURPOSE  OF  INVESTIGATIONS .512 

OCCURRENCE  OF  FLAG  SMUT 512 

LOSSES  DUE  TO  FLAG  SMUT 513 

SYMPTOMS  514 

THE  CAUSAL  FUNGUS  ( Urocystis  tritici  Kcke.) 515 

DISSEMINATION 516 

CONTROL  MEASURES 519 

Experiments  in  Control  by  Seed  Treatment 519 

Control  by  Crop  Rotation 521 

Experiments  in  Control  by  Date  of  Seeding 522 

VARIETAL  RESISTANCE 523 

Experimental  Work  to  Determine  Varieties  Completely  Resistant 524 

Varieties  Apparently  Highly  Resistant 526 

Wheat  Varieties  Generally  Grown  in  the  Flag  Smut  Area 530 

INDEX  OF  ALL  WHEAT  VARIETIES  TESTED,  SHOWING  RESIST- 
ANCE AND  SUSCEPTIBILITY  TO  FLAG  SMUT 531 

CONCLUSIONS 537 

LITERATURE  CITED   .  ..538 


SUMMARY 

Flag  smut  has  caused  severe  damage  to  wheat  in  Australia  and  local  damage 
in  Japan  and  South  Africa.  It  is  known  to  occur  in  India  and  China  but  the 
extent  of  the  loss  caused  is  not  known. 

The  disease  was  found  first  in  the  United  States  in  1919,  near  Granite  City, 
Madison  county,  Illinois,  and  is  thought  to  have  been  introduced  from  Australia. 
It  has  now  spread  over  an  area  in  Illinois  about  fifty  miles  long  and  five  to 
fifteen  miles  wide.  An  infested  area  in  Missouri  adjacent  to  that  in  Illinois 
includes  only  four  fields.  The  disease  is  spreading  at  a  rather  steady  rate. 

As  yet  severe  losses  by  the  disease  have  not  been  extensive  in  the  infested 
area  in  this  country.  However,  rare  cases  of  an  infection  up  to  30  percent  in 
parts  of  fields  indicates  that  the  disease  may  cause  severe  loss  if  no  precautions 
are  taken  to  hold  it  in  check.  In  Australia  the  effects  are  said  to  be  cumulative. 

One  of  the  chief  sources  of  infection  is  the  spores  that  cling  to  the  seed,  which 
contaminate  threshing  machines,  wagon  beds,  grain  bins,  etc.  A  second  source 
is  the  spores  in  the  soil,  which  may  come  from  infested  straw  and  manure,  or 
be  carried  by  wind  or  streams,  or  by  animals  or  vehicles  passing  thru  the  in- 
fested area. 

It  is  not  known  how  long  the  spores  will  live  in  the  soil,  but  it  is  known 
that  some  of  them  survive  the  winter  months. 

Because  of  the  fact  that  the  spores  easily  survive  the  summer  and  are 
present  to  infect  fall-sown  wheat,  it  is  especially  important  that  fields  growing 
smutty  wheat  be  sown  to  other  crops  the  following  year.  Any  other  crop  may 
be  used,  as  flag  smut  affects  only  wheat. 

In  experiments  in  which  seed  was  first  smutted  and  then  treated  with  fungi- 
cides, it  was  found  that  the  disease  was  practically  controlled  in  the  plots  where 
copper  sulfate  and  lime,  and  where  copper  carbonate  had  been  used.  The  treat- 
ments, however,  failed  to  control  the  disease  when  the  seed  was  sown  in  furrows 
in  which  spores  of  flag  smut  had  been  previously  dusted. 

In  a  three-year  experiment  to  determine  the  effect  of  the  time  of  sowing 
on  the  development  of  flag  smut,  it  was  found  that  the  wheat  sown  after  the 
first  of  November  or  in  the  spring  was  much  less  subject  to  flag  smut  than  the 
wheat  sown  in  the  early  fall.  This  was  doubtless  owing  to  the  fact  that  tempera- 
tures at  that  time  are  too  low  for  spore  germination.  Sowings  made  after  the 
middle  of  November  were  smut  free,  but  the  yields  were  very  low. 

In  the  course  of  three  years'  experiments  nearly  two  hundred  varieties  or 
strains  of  wheat  were  tested  for  susceptibility  to  flag  smut.  The  seed  was 
thoroly  smutted  with  the  spores  of  the  fungus  and  sown  in  the  infested  area. 
Some  fourteen  varieties  or  strains  were  found  to  be  immune  and  forty-one 
others  were  highly  resistant.  Some  of  these  are  adapted  to  the  conditions  ex- 
isting in  the  infested  area,  while  others  are  not.  Several  of  the  adapted  varieties 
are  being  increased  for  wider  sowing  and  for  further  testing  in  this  locality. 

Immune  varieties  that  are  adapted  to  the  infested  area  include  Beechwood, 
Ful caster  (Marvelous  and  Stoner),  Imperial  Amber,  Bed  May  (Early  Harvest), 
Bed  Bock,  and  Shepherd. 

Of  the  varieties  commonly  grown  in  the  infested  area,  Harvest  Queen  (Bed 
Cross  or  Salzer's  Prizetaker)  was  found  to  be  the  most  susceptible  varietj'.  Flint 
(May),  Gipsy  (Niagara),  Bed  Wave,  Jones  Fife,  and  Fultz  also  showed  a  high 
percentage  of  infection. 


FLAG  SMUT  OF  WHEAT,  WITH  SPECIAL 

REFERENCE  TO  VARIETAL 

RESISTANCE 

BY  W.  H.  TISDALE,  G.  H.  DUNCAN,  AND  C.  E.  LEIGHTY" 

INTRODUCTION 

The  discovery  of  flag  smut  (Urocystis  tritici  Kcke.)  in  May,  1919, 
in  some  of  the  wheat  fields  of  Madison  county,  Illinois,  added  another 
pest  to  the  already  rather  long  list  of  troubles  known  to  affect  wheat  in 
the  United  States.  Knowing  the  importance  of  flag  smut  as  a  destruc- 
tive parasitic  fungus  in  Australia,  American  plant  pathologists  and 
agronomists,  on  learning  of  its  occurrence  in  this  country,  at  once 
became  interested  in  what  might  be  its  capacity  for  crop  destruction 
under  changed  conditions  of  environment,  in  its  epidemiology,  and  in 
methods  for  its  control. 

Fortunately,  flag  smut  thus  far  has  been  found  in  but  a  limited 
area  in  southwestern  Illinois  and  on  four  farms  in  St.  Louis  county, 
Missouri.  To  be  sure,  it  has  never,  even  under  the  most  favorable 
conditions,  proved  so  destructive  as  bunt  or  stinking  smut  of  wheat, 
but  its  effects  are  none  the  less  worthy  of  serious  consideration. 
Losses  amounting  to  as  much  as  10  to  20  percent  are  not  uncommon ; 
and  these  losses,  added  to  those  caused  by  rusts  and  by  other  smuts, 
by  scab,  and  other  diseases  peculiar  to  the  wheat  crop,  form  no  incon- 
siderable part  in  an  aggregate  reduction  of  yield  that  on  the  whole  is 
enormous.  The  research  herein  reported  has  contributed  materially 
to  the  existing  knowledge  of  the  habits  and  life  history  of  the  flag 
smut  organism,  the  etiology  of  the  disease,  and  methods  for  its  con- 
trol. Quite  the  most  important  result  of  these  studies  has  been  the 
discovery  of  a  number  of  important  varieties  of  wheat  that  are  either 
immune  from,  or  highly  resistant  to,  flag  smut.  These  varieties  offer 
the  most  promising  means  of  controlling  this  destructive  disease. 


•W.  H.  Tisdale,  Pathologist  in  Charge  of  Cereal  Smut  Investigations,  Office 
of  Cereal  Investigations,  Bureau  of  Plant  Industry,  U.  S.  Department  of  Agri- 
culture ;  G.  H.  Dungan,  Associate  in  Crop  Production,  University  of  Illinois  Agri- 
cultural Experiment  Station;  C.  E.  Leighty,  Agronomist  in  Charge  of  Eastern 
Wheat  Investigations,  Bureau  of  Plant  Industry,  U.  S.  Department  of  Agriculture. 

511 


512  BULLETIN  No.  242  [April, 

HISTORY  AND  PURPOSE  OF  INVESTIGATIONS 

Immediately  after  the  discovery  of  flag  smut  of  wheat  in  Madison 
county,  Illinois,  in  1919,  arrangements  were  made  for  a  cooperative 
investigation  of  the  disease  by  the  Office  of  Cereal  Investigations, 
Bureau  of  Plant  Industry,  U.  S.  Department  of  Agriculture,  and  the 
University  of  Illinois  Agricultural  Experiment  Station.  The  pur- 
pose of  this  bulletin  is  to  discuss  the  results  of  these  investigations: 
namely,  the  history  of  the  occurrence  of  flag  smut,  the  losses  caused, 
a  description  of  the  disease  and  the  causal  organism,  the  dissemination 
of  the  smut  fungus,  and  finally,  but  most  important,  the  results 
obtained  thru  experiments  conducted  in  the  infested  area,  near 
Granite  City,  Illinois,  for  the  purpose  of  controlling  the  disease.  It 
is  very  desirable  that  the  wheat  farmers  of  the  United  States  be 
informed  as  to  the  nature  of  flag  smut  and  the  available  means  of 
holding  it  in  check. 

OCCURRENCE  OF  FLAG  SMUT 

Flag  smut  of  wheat  is  now  known  to  occur  in  a  number  of  coun- 
tries thruout  the  world.  The  first  reports  of  its  occurrence  came  from 
Australia,  where  it  was  reported  by  the  South  Australian  Commission 
on  Diseases  of  Cereals  in  1868.16  Since  that  time  it  has  been  found 
to  be  widely  distributed  in  South  Australia  and  to  occur  in  Northern 
Victoria,  New  South  Wales,  and  Queensland.16  It  was  found  by 
Hori11  in  Japan  in  1895,  and  by  Sydow  and  Butler23  in  India  in 
1906.  In  1920  Putterill21  reported  the  occurrence  of  the  disease  in 
South  Africa,  where  it  is  commonly  known  as  "Tulp  brand"  or 
"Stoel  brand."  He  thinks  that  it  has  been  present  in  South  Africa 
for  a  number  of  years.* 

Flag  smut  was  first  found  in  the  United  States  in  Madison  county, 
Illinois,  on  May  5,  1919.12  In  that  year  it  was  found  in  a  number  of 
fields  in  the  vicinity  of  Granite  City,  where  it  was  first  noted.22-  24 
In  1920,  in  an  extensive  survey  made  by  the  Office  of  Plant-Disease 
Survey,  Bureau  of  Plant  Industry,  U.  S.  Department  of  Agriculture, 
in  cooperation  with  the  Illinois  State  Department  of  Agriculture, 
flag  smut  was  found  in  111  fields  in  the  county  in  an  area  comprizing 
about  47  square  miles.22'  24  In  1921  the  disease  was^  found  to  be 
spread  over  an  area  of  65  square  miles  in  Madison  county  and  15 
square  miles  in  St.  Clair  county,  Illinois.8  The  survey  of  19228 
showed  flag  smut  to  be  present  in  two  additional  counties  in  Illinois : 
viz.,  Jersey,  north  of  Madison  county,  and  Monroe,  south  of  St.  Clair 
county,  and  also  in  St.  Louis  county,  Missouri.  The  infested  area  in 


"This  and  similar  reference  numbers  refer  to  "Literature  Cited,"  page  538. 

'Since  the  preparation  of  this  manuscript  the  authors  have  had  access  to 
a  translation  of  a  Japanese  paper  written  by  Miyake,  in  1912,  in  which  he  notes 
the  occurrence  of  flag  smut  in  China.38 


19183]  FLAG  SMUT  OP  WHEAT  513 

Illinois  is  about  fifty  miles  long  and  five  to  fifteen  miles  wide.  The 
infested  area  in  Missouri  is  adjacent  to  that  in  Illinois  and  includes 
only  four  fields.  The  enlargement  of  the  area  from  year  to  year 
probably  has  not  been  due  entirely  to  spread  of  the  disease  but  to 
wider  and  more  thoro  search.  The  survey  has  been  limited  because 
of  lack  of  funds  and  men  available  for  the  work.  The  indications 
are  that  some  of  the  recently  discovered  infestations  have  existed  for 
a  number  of  years.  The  records  do  indicate,  however,  that  the  disease 
is  spreading  at  a  rather  steady  rate. 

According  to  Brittlebank,2  it  is  probable  that  flag  smut  was  intro- 
duced into  this  country  from  Australia.  He  states  that  during  the 
year  1918,  51/2  million  bushels  of  wheat  were  exported  to  the  United 
States  from  Australia.  This  wheat  was  supposed  to  be  used  for 
milling  purposes  only,  but  some  of  the  contaminated  by-products  such 
as  bran,  or  even  the  grain  itself,  might  have  escaped  into  the  fields 
thru  some  of  the  numerous  possible  agencies.  The  fact  that  flag  smut 
was  found  the  next  season  following  the  importation  of  Australian 
wheat  seems  to  furnish  considerable  evidence  for  Brittlebank 's  theory 
that  the  disease  was  introduced  into  this  country  from  Australia. 

LOSSES  DUE  TO  FLAG  SMUT 

It  is  possible  for  the  damage  caused  by  flag  smut  to  be  heavier 
than  might  be  suspected  from  looking  at  the  mature  wheat  crop. 
Diseased  plants  generally  are  much  dwarfed  and  the  smutty  plants 
seldom  produce  heads,  but  die  before  the  wheat  is  ripe.  Thus  the 
diseased  plants  may  easily  be  overlooked  and  the  thin  stand  and  light 
harvest  not  be  attributed  to  the  smut. 

According  to  Brittlebank,1  the  disease  may  cause  unsuspected 
damage  thruout  the  growing  season.  In  1905  Me  Alpine15  stated  that 
in  some  seasons  in  Australia  severe  losses  had  been  caused  by  the 
disease.  In  1910  the  same  writer16  made  the  following  statement :  "In 
Victoria  as  much  as  half  the  crop  may  be  lost  thru  it  and  in  New 
South  Wales,  Cobb  has  shown  it 'to  be  equally  bad.  Where  wheat  is 
grown  year  after  year  and  no  precautions  taken  against  this  disease, 
the  effects  are  cumulative.  This  will  account  for  the  widespread  and 
injurious  effects  of  this  disease  in  many  wheat  growing  districts." 
Later  reports  made  by  Australian  writers  seem  to  bear  out  the  state- 
ments made  by  McAlpine  that  the  effects  are  cumulative.  Brittle- 
bank,1  in  1920,  says,  "Considering  that  rust  epidemics  are  few  and 
far  between,  while  flag  smut  is  annually  taking  toll  of  from  5  percent 
to  nearly  70  percent,  the  total  loss  caused  by  rust  sinks  into  insignifi- 
cance when  compared  with  that  resulting  from  flag  smut."  Rust  is 
regarded  by  some  as  being  the  most  destructive  disease  of  wheat  in 
Australia.1 


514  BULLETIN  No.  242  [April, 

Hori11  reports  considerable  local  damage  to  the  wheat  crop  from 
flag  smut  in  Japan  as  early  as  1895.  No  recent  reports  have  been 
received  from  that  country.  The  disease  is  known  to  occur  in  India23 
but  there  are  no  available  reports  of  the  losses  caused  by  it.  Putterill21 
makes  the  following  statement  regarding  the  losses  due  to  flag  smut  in 
South  Africa:  "During  the  last  two  or  three  years,  wheat  farmers 
at  Zeerust,  in  the  Marico  District  of  the  Transvaal,  have  been  con- 
siderably alarmed  at  the  loss  in  their  wheat  crops  sustained  thru  the 
ravages  of  this  smut.  While  the  total  loss  up  to  now  may  not  be 
considered  very  great  in  that  district,  yet  in  some  wheat  fields  lately 
visited  almost  half  the  crop  was  found  to  be  affected." 

Flag  smut  has  not  yet  caused  any  very  serious  losses  in  the  United 
States.  In  most  fields,  infections  have  been  scattered  and  difficult  to 
find.  In  some  cases,  however,  fields  have  been  found  showing  as  many 
as  5  percent  of  the  plants  infected.  In  extremely  rare  cases,  from 
5  to  30  percent  of  infected  plants  in  parts  of  fields  has  been  reported, 
and  in  one  field  of  thirty-five  acres  an  average  infection  of  17  percent 
was  found.8  The  fact  that  seed  treatment  and  other  measures,  such 
as  the  use  of  resistant  varieties,  have  been  adopted  for  holding  the 
disease  in  check  no  doubt  accounts,  to  a  marked  extent,  for  the  low 
percentages.  Furthermore,  the  facts  concerning  the  cumulative  effects 
of  the  disease  in  Australia  may  be  significant  in  this  country.  It  is 
not  known  how  long  the  spores  of  the  flag  smut  fungus  will  live  in 
the  fields  in  the  infested  area,  but  it  is  known  that  some  of  them  will 
live  over  winter  in  the  soil  and  still  be  capable  of  germinating  and 
infecting  wheat  plants.*  If  the  fungus  is  able  to  live  in  the  soil  in 
this  country,  as  it  does  in  Australia,  its  effects  no  doubt  will  be  cumu- 
lative, as  they  are  there,  provided  effective  control  measures  are  not 
employed. 

SYMPTOMS 

Flag  smut  of  wheat  occurs  in  the  leaf  blades  and  sheaths,  forming 
black  stripes  running  lengthwise.  (Figs.  1  and  2.)  In  the  early 
stages  these  stripes  are  somewhat  lighter  than  the  green  color  of  the 
normal  leaf;  later  they  become  lead-colored  and  finally  black  because 
of  the  presence  of  the  dark-colored  spores  produced  by  the  fungus. 
They  are  commonly  more  noticeable  in  the  upper  leaves,  and  may  be 
seen  even  before  jointing  is  apparent  in  the  plants.  The  stems  (culms) 
often  show  these  black  stripes  also.  Infected  plants  usually  are  more 
or  less  dwarfed.  The  leaves  and  sheaths  become  twisted  in  some 
cases,  and  the  infected  culms  rarely  head  out  or  produce  seed.  Where 
heads  do  appear  on  infected  culms,  the  black  stripes  may  be  present 
on  the  glumes  at  the  base  of  the  head  and  usually  are  present  on  the 
culms  just  below  the  head.  One  or  more  sound  culms  with  normal 


•Unpublished  data  furnished  by  Miss  M.  A.  Griffiths,  Office  of  Cereal  In- 
vestigations, U;  S.  Department  of  Agriculture. 


19SS]  FLAG  SMUT  OF  WHEAT  515 

heads  often  may  be  found  on  smutty  plants,  but  it  is  not  uncommon 
to  find  infected  plants  without  a  single  sound  culm.  The  degree  of 
culm  infection  seems  to  vary  with  the  variety. 

Stem  smut  of  rye,  with  which  flag  smut  was  formerly  thought  to  be 
identical,  differs  from  it  in  that  the  rye  disease  is  most  noticeable  on 
the  culms,  which  it  more  or  less  distorts,  while  the  leaves  show  prac- 
tically no  distortion  and  the  culms  generally  produce  heads  even  tho 
they  are  not  well  filled.  It  is  caused  by  a  different  tho  related  or- 
ganism, as  is  shown  below,  and  will  not  pass  from  rye  to  wheat. 

THE  CAUSAL  FUNGUS  (Urocystis  tritici  Kcke.) 

Flag  smut  of  wheat  is  caused  by  a  minute  parasitic  plant,  or 
fungus,  belonging  to  the  group  of  fungi  which  produces  the  disease  of 
plants  commonly  known  as  smut.  More  familiar  examples  of  dis- 
eases caused  by  this  type  of  fungus  are  loose  smut  and  bunt  of  wheat 
and  the  loose  and  covered  smuts  of  oats.  More  closely  related,  how- 
ever, are  the  smut  of  onions,  which  causes  considerable  damage  to 
the  onion  crop  of  the  United  States,  and  the  stem  smut  of  rye,  which 
is  less  destructive.  Wolff,25  in  1873,  thought  that  the  fungus  causing 
flag  smut  of  wheat  was  identical  with  the  one  causing  stem  smut  of 
rye  and  called  it  Urocystis  occulta  Rabh.,  which  is  the  rye  form. 
Kornicke,13  in  1877,  after  making  a  careful  morphological  study  of 
the  forms  from  wheat  and  rye,  decided  that  there  was  sufficient  differ- 
ence to  justify  making  the  wheat  form  a  distinct  species,  so  he  called 
it  Urocystis  tritici  Kcke.  McAlpine,10  after  repeated  cross  inocula- 
tions of  wheat  and  rye  with  their  respective  Urocystis  forms,  agreed 
with  Kornicke  in  concluding  that  they  were  different.  Previous  to 
these  studies  by  McAlpine  the  disease  was  reported  on  wheat  in 
Japan1 1  and  India23  as  being  caused  by  Urocystis  occulta  Rabh.  Since 
McAlpine 's16  report  it  has  been  agreed  generally  that  the  Urocystis 
species  on  wheat  and  on  rye  are  different. 

The  black  stripes  appearing  on  infected  wheat  plants  are  filled 
with  numerous  minute,  dark  colored  spores  of  the  fungus  (Fig.  3,  A), 
which,  in  mass,  appear  black  and  produce  the  black  color  of  the 
stripes.  The  spores  contain  from  one  to  five  large  cells,  which  are 
capable  of  germinating.  These  large  cells  are  incased  in  an  outer 
layer  of  smaller,  bladder-like,  sterile  cells,  making  what  is  commonly 
termed  a  spore  ball.  These  spore  balls  are  15  to  35  microns,  or  an 
average  of  24  microns  (.001  inch),  in  diameter.  The  outer  protective 
envelop  of  sterile  cells  serves,  no  doubt,  as  an  aid  to  dissemination 
by  wind  and  water  by  causing  the  spores  to  float. 

Germination  of  the  spores  takes  place  by  small  germ  tubes,  or 
promycelia,  arising  from  the  larger,  inner  cells  (Fig.  3,  B).  Gen- 
erally one  to  two,  and  occasionally  all,  of  the  cells  in  the  spore  ball 


516  BULLETIN  No.  242  [April, 

germinate.  The  promycelium,  which  may  or  may  not  be  septate, 
bears  at  its  apex  two  to  six,  more  commonly  three,  thread-like  append- 
ages, or  secondary  spores,  known  as  sporidia.  These  sporidia,  usually 
of  unequal  length,  are  at  first  unicellular,  but  may  divide  later  into 
two  or  three  cells.  In  some  cases  they  grow  out  into  variously  curved 
filaments.  These  sporidia  in  turn  germinate,  producing  minute, 
thread-like  tubes,  or  hyphae,  which,  if  in  contact  with  the  young  wheat 
seedling  as  the  seed  germinates,  penetrate  its  tender  tissue.  These 
hyphae,  which  scarcely  can  be  seen  with  the  aid  of  the  microscope, 
grow  up  thru  the  tissues  of  the  young  wheat  plant,  from  which  they 
obtain  food.  In  the  spring,  the  smut  fungus,  after  it  has  spread  thru 
the  tissues  of  the  wheat  and  after  its  food  supply  has  become  some- 
what exhausted,  begins  to  produce  the  dark  colored  spores,  which, 
in  mass,  appear  as  long  black  stripes,  so  typical  of  the  disease.  With 
the  ripening  of  spores,  the  epidermis  of  the  leaf  along  the  stripes 
breaks  open,  thus  setting  free  the  spores  for  a  further  contamination 
of  seed  and  soil.27 


Wheat  plants  are  attacked  by  flag  smut  chiefly  from  two  sources. 
One  source  is  thru  smut  spores  that  cling  to  the  seed.  In  threshing 
grain  from  infested  fields  a  large  proportion  of  the  spores  are  knocked 
out  of  the  diseased  plants  and  scattered  over  the  grain.  They  also 
lodge  in  the  threshing  machine  and  later  become  mixed  with  seed 
threshed  from  clean  fields.  Contaminated  wagon  beds,  grain  bins, 
bags,  or  other  objects  with  which  grain  comes  in  contact  may  serve 
as  disseminating  agents  for  the  fungus. 

When  contaminated  grain  is  sown  and  germinates,  the  adhering 
spores  also  germinate.  The  germ  tube  penetrates  the  young  wheat 
seedling,  grows  up  thru  its  tissues,  and  appears  in  the  spring  as  smut 
stripes  in  the  wheat  plant. 

The  other  source  of  infection  is  thru  spores  in  the  soil.  McAlpine16 
proved  that  infested  straw  and  manure  from  horses  fed  on  diseased 
straw,  when  placed  on  wheat  land,  were  sources  of  infection. 
Hamblin9  also  says:  "It  is  known  that  horses  and  cattle  fed  on  dis- 
eased hay  have  passed  the  spores  uninjured  and  capable  of  germina- 
tion."  Putterill21  states  that  the  spores  may  be  blown  about  by  wind, 
carried  on  the  hoofs  of  animals,  or  transported  by  irrigation  water. 
While  the  latter  agent  would  not  be  a  factor  in  the  present  infested 
area  and  surrounding  territory  in  this  country,  flood  water  from 
streams  may  serve  the  same  purpose.  There  is  no  particular  reason 
why  spores  may  not  be  carried  from  field  to  field  or  from  one  locality 
to  another  on  the  clothes  of  man  and  by  animals,  including  birds, 
and  on  any  vehicle  or  exposed  product  leaving  or  passing  thru  the 
infested  area,  especially  during  and  near  harvest  time,  when  abundant 


FIG.  1. — PORTIONS  OF  WHEAT  PLANTS  SHOWING  THE  BLACK  STRIPES 
CAUSED  BY  FLAG  SMUT 


FIG.  2. — PORTION  OF  WHEAT  LEAF,  GREATLY  ENLARGED,  SHOWING 

THE  BLACK  STRIPES  CAUSED  BY  FLAG  SMUT.     NOTE  THAT 

SOME  OF  THESE  STRIPES  HAVE  RUPTURED 


1923]  FLAG  SMUT  OP  WHEAT  519 

spore  material  is  being  liberated  from  the  diseased  plants.  The  spores 
carried  by  these  agencies  may  fall  on  land  where  wheat  is  to  be  sown 
and  thus  spread  the  disease. 

In  fields  where  a  diseased  crop  has  been  harvested  the  spores  live 
over  on  the  stubble  and  in  the  soil  until  fall.  A  small  percentage  of 
spores  is  known  to  overwinter  in  the  soil  at  Granite  City,  Illinois,  as 
previously  mentioned,  but  it  is  not -known  whether  these  spores  which 
have  overwintered  will  live  until  time  for  sowing  wheat  the  next 
autumn.  In  Australia,  Brittlebank1  says,  "Contamination  of  the  soil 
is  the  most  difficult  problem  in  dealing  with  the  control  of  flag  smut. ' ' 
The  climatic  conditions  in  the  infested  area  in  this  country  may  or 
may  not  permit  the  organism  to  live  in  the  soil  in  abundance  and  for 
long  periods  of  time,  as  it  does  in  Australia.  These  questions  remain 
to  be  answered. 

CONTROL  MEASURES 

Flag  smut  may  be  held  in  check  and  reduced  to  a  minimum  by 
employing  judicious  quarantine,  crop  rotation,  seed  treatment,  and 
other  sanitary  measures,  and  by  growing  resistant  varieties  of  wheat. 
The  soil  and  weather  conditions  under  which  the  wheat  is  sown  also 
influence  the  development  of  the  disease.  Certain  quarantine  and 
farm  sanitation  measures  have  been  employed  in  the  infested  area  in 
this  country  in  cooperation  with  the  Illinois  State  Department  of  Agri- 
culture. They  consist  in  the  regulation  of  shipments  of  infested  grain 
and  straw,  the  disinfection  of  farm  machinery  leaving  the  infested 
area,  etc.  The  burning  of  infested  straw  and  stubble,  which  is  recom- 
mended in  Australia,9-  1G  would  be  of  value  in  reducing  the  spore  ma- 
terial present.  These  measures  are  discussed  in  detail  in  Circular 
No.  4  of  the  Illinois  State  Department  of  Agriculture,  "Flag  Smut 
of  Wheat."8 

EXPERIMENTS  IN  CONTROL  BY  SEED  TREATMENT 

The  following  experiments  were  undertaken  to  learn  whether 
spores  of  flag  smut  carried  on  seed  wheat  can  be  destroyed  by  treating 
the  seed  with  certain  fungicides.  For  this  purpose  a  lot  of  seed  of 
the  Harvest  Queen  (Red  Cross)  variety  was  thoroly  smutted  with 
viable  spores  of  Urocystis  tritici.  After  treating  this  infested  seed 
with  the  different  fungicides  in  the  manner  described  below,  it  was 
sown  in  the  soil  in  the  infested  area  at  Granite  City,  Illinois.  The 
various  treatments  and  the  results  obtained  are  shown  in  Table  1. 

A  number  of  different  strengths  of  copper-sulfate  solution  and 
formaldehyde  were  used  and  also  a  number  of  methods  of  application, 
but  none  of  them  proved  to  be  more  satisfactory  than  the  strengths 
and  methods  of  application  commonly  employed  and  only  these  latter 
are  reported  in  the  table.  Copper  sulfate  was  used  at  the  rate  of  1 
pound  to  5  gallons  of  water.  The  seed  was  submerged  for  ten  min- 


520 


BULLETIN  No.  242 


[April, 


TABLE  1. — EFFECTS  OF  SEED  TREATMENT  ON  THE  CONTROL  OF  FLAG  SMUT  IN 

HARVEST  QUEEN  (BED  CROSS)  WHEAT  WHEN  THE  SEED  WAS  THOROLY  SMUTTED 

Seed  sown  in  soil  where  flag  smut  had  occurred  the  previous  year.     Experiment 

plots,  Granite  City,  Illinois. 


Treatment 

Percentage  of  infected  plants 

1920 

1921 

1922 

3-year 
average 

Untreated  

27.0 

17.2 

6!6 
0.0 

25.6 
1.9 
.4 
.8 
1.8 
21.7 
17.6 

23.26 

.26 
.60 

Chlorophol  (.3  percent  solution). 

Copper  carbonate  (dust)  

Copper  sulfate-lime  (dip)  

trace 
trace 

Formaldehyde  (1  :320  dip)  

Sterilac  (1:500)  

Sterilac  (1:1000)  

"This  name  is  now  applied  to  the  flag  smut  susceptible  variety,  with  white 
glabrous  chaff,  red  kernels,  and  beardless  heads,  which  was  largely  grown  in 
southern  Illinois,  at  the  time  flag  smut  was  discovered,  under  the  name  "Salzer's 
Prizetaker."  The  true  Salzer's  Prizetaker  is  beardless,  with  glabrous  red  chaff 
and  white  kernels.  This  white-chaffed  variety  is  sometimes  known  also  as  "Red 
Cross,"  but  this  name  is  objectionable  as  there  is  a  red-chaffed  variety  known 
by  the  same  name. 

utes  in  this  solution  and  then  for  five  minutes  in  lime  water  contain- 
ing 1  pound  of  lime  to  10  gallons  of  water.  Formaldehyde  was  used 
at  the  rate  of  1  part  in  320  parts  of  water  (1  pint  in  40  gallons  of 
water).  The  seed  was  soaked  for  ten  minutes  in  this  solution  and 
then  covered  for  four  hours,  after  which  it  was  spread  out  to  dry 
before  sowing. 

From  the  table  it  will  be  noted  that,  in  1922,  seed  from  all  treat- 
ments produced  some  infected  plants.  These  infections,  however, 
except  in  the  case  of  the  treatment  with  Sterilac,  where  the  percentage 
of  infection  was  very  high,  may  reasonably  be  accounted  for  by  the 
presence  of  spores  in  the  soil,  since  the  treated  seed  was  sown  in  soil 
where  flag  smut  had  occurred  in  wheat  the  previous  year.  From  these 
results  it  may  be  said,  in  general,  that  nearly  all  the  spores  carried 
on  the  seed  can  be  destroyed  by  seed  treatment. 

Copper  carbonate  dust,  which  has  been  used  successfully  in  Aus- 
tralia6 and  in  the  Pacific  coast  states10-18  for  controlling  bunt  in 
wheat,  gave  good  results  in  the  single  season  it  was  tried.  (It  was 
used  at  the  rate  of  2  ounces  per  bushel  of  seed.)  Chlorophol,  an 
organic  mercury  compound  of  recent  development,  was  fairly  effective 
in  destroying  seed-borne  spores.  (The  seed  was  soaked  in  a  .3-percent 
solution  of  Chlorophol  for  one  hour  and  dried  before  sowing.) 
Sterilac,  another  newly  developed  compound,  was  used  without 
success. 

Of  the  treatments  used,  copper  carbonate  is  the  easiest  to  apply 
and  does  not  cause  seed  injury ;  rather,  it  sometimes  appears  actually 
to  stimulate  the  seedlings.  The  grain  is  more  easily  handled  during 
and  after  this  dust  treatment  than  it  is  when  treated  with  copper 
sulfate  or  by  other  wet  methods.  Heald  and  Smith10  have  devised  a 


W2S]  FLAG  SMUT  OF  WHEAT  521 

TABLE  2. — EFFECTS  OF  SEED  TREATMENT  ON  THE  CONTROL  OF  FLAG  SMUT  IN 
HARVEST  QUEEN  (RED  CROSS)  WHEAT  WHEN  THE  SEED  WAS  SOWN  IN  SOIL 

HEAVILY  INOCULATED  WITH  SPORES  OF  FLAG  SMUT 
Seed  treated  and  sown  in  experiment  plots,  Granite  City,  Illinois,  October  4,  1921. 


Treatment 

Percentage 
of  infected 
plants 

Percentage  of 
smutty  culms  on 
infected  plants 

Untreated.  .             

•    19  3 

36  7 

Copper  sulfate-lime  

13.0 

38.6 

Copper  carbonate  

16.0 

32.4 

machine  for  dusting  grain  which  consists  of  a  wooden  drum  so  mounted 
that  by  revolving  it  the  dust  and  grain  are  thoroly  mixed.  A  re- 
volving barrel  churn  or  any  device  which  will  insure  a  thoro  mixing 
will  serve  the  purpose  if  no  special  machine  is  available.  It  is  very 
important  to  have  the  dust  so  thoroly  applied  that  each  kernel  of  wheat 
will  be  covered  with  a  thin  film  over  its  entire  surface.1 

Altho  treatments  with  copper  sulfate  and  lime  and  with  copper 
carbonate  were  very  successful  when  the  seed  was  sown  in  soil  where 
infected  wheat  had  grown  the  preceding  year,  they  failed  to  prevent 
the  disease  when  the  treated  seed  was  sown  in  furrows  in  which 
spores  of  flag  smut  had  been  previously  dusted  and  mixed  with  the 
soil  by  means  of  a  small  hand  plow.  To  be  effective  under  these 
conditions  the  fungicide  necessarily  would  have  to  remain  active  until 
after  the  time  the  seed  had  germinated,  when  infection  would  take 
place.  However,  even  tho  the  disinfectant  should  remain  active  until 
that  time,  there  might  be  infection  from  the  spores  in  the  soil  that 
were  near  enough  the  young  plant  to  infect  it  but  too  far  from  the 
seed  to  be  destroyed  by  the  disinfectant.  The  results  of  this  one- 
year  study  of  the  duration  of  protection  by  these  fungicides  are 
shown  in  Table  2.  The  amount  of  inoculum  present  in  the  furrows 
in  which  the  grain  was  sown  was  larger  than  ordinarily  would  be 
expected  «under  natural  conditions;  still,  it  shows  that  control  by 
seed  treatment  cannot  be  assured  where  the  soil  becomes  infested 
with  viable  spores. 

In  accordance  with  quarantine  regulations,  commercial  seed  wheat 
sown  by  wheat  grower's  in  the  infested  area  was  treated  with  copper 
sulfate  and  lime,  yet  traces  of  Tsmut  were  found  in  some  of  these 
fields.  This,  in  all  probability,  was  due  to  the  presence  of  spores  in 
the  soil.  Australian  writers  are  agreed  that  seed  treatment  kills  seed- 
borne  spores  but  that  it  is  less  effective  in  controlling  smut  where  the 
soil  is  infested. 

CONTROL  BY  CROP  ROTATION 

Wheat  sown  in  the  infested  area  but  in  fields  in  which  flag  smut  has 
not  occurred  for  one  or  more  years  previously  is  less  subject  to  smut 


'Care  should  be  taken  in  handling  copper  carbonate  dust  to  prevent  inhaling 
it,  as  it  may  cause  irritation  of  the  nose  and  throat. 


522  BULLETIN  No.  242  [April, 

than  if  sown  in  fields  known  to  have  been  infested  the  preceding  year. 
Because  of  the  fact  that  the  spores  easily  survive  the  summer  and  are 
present  to  infect  fall-sown  wheat,  it  is  especially  important  that  fields 
growing  smutty  wheat  be  sown  to  other  crops  the  following  year. 

McAlpine,16  Brittlebank,1  and  Hamblin9  of  Australia,  and 
Putterill21  of  South  Africa  all  recommend  crop  rotation  as  a  means 
of  reducing  the  amount  of  flag  smut  to  a  minimum.  There  are  some 
indications  from  survey  records8  that  rotation  will  be  of  some  value  in 
this  country,  as  fields  in  the  infested  area  which  previously  had  grown 
crops  other  than  wheat  were  found  to  have  less  flag  smut  than  fields 
which  had  been  cropped  to  wheat  for  a  number  of  years  and  in  which 
flag  smut  was  known  to  occur.  These  records  indicate  that  the  effects 
of  flag  smut  in  this  country,  as  in  Australia,  may  be  cumulative  when 
susceptible  wheat  is  grown  continuously  on  infested  land. 

Whether  or  not  smut  spores  can  survive  in  the  soil  thru  the  second 
year  and  infect  a  wheat  crop  when  the  land  has  not  grown  wheat  for 
one  year  remains  to  be  determined.  Final  advice  concerning  rota- 
tions, therefore,  cannot  be  given  at  this  time.  However,  it  is  evident 
that  at  least  one  year  should  intervene  between  wheat  crops  on  the 
same  land,  and  it  is  probable  that  two  or  more  years  must  pass  before 
the  land  is  entirely  free  of  viable  spores.  Inasmuch  as  this  disease 
does  not  affect  other  crops  than  wheat,  no  limitation  is  imposed,  so 
far  as  the  disease  is  concerned,  as  to  what  crops  should  be  grown  in 
the  rotation.  However,  straw,  manure,  or  other  material  that  may 
contain  smut  spores  should  not  be  returned  to  the  soil  in  the  mean- 
time, as  infection  may  come  from  these  sources.  A  straw  mulch  on 
potatoes,  for  example,  may  add  the  smut  spores  to  the  soil.  If  manure 
or  other  material  that  possibly  may  contain  the  smut  spores  is  to  be 
applied,  the  safest  place  in  the  rotation  to  apply  it  is  on  the  wheat 
stubble. 

» 

EXPERIMENTS  IN  CONTROL  BY  DATE  OF  SEEDING 

Wheat  sown  early  in  the  fall  is  more  subject  to  infection  by  flag 
smut  than  that  sown  later.  According  to  Australian  writers1-  9> 16 
early  and  self-sown  (volunteer)  wheat  suffers  most  from  flag  smut. 
They  also  state  that  wheat  sown  in  dry  soil  is  more  subject  to  the 
disease  than  wheat  sown  following  a  rain.  This,  they  claim,  is  be- 
cause of  the  fact  that  during  a  dry  season  the  spores  remain  unger- 
minated  in  the  soil  and  when  the  rains  come  both  spores  and  seed 
germinate  and  infection  of  the  seedlings  takes  place,  while,  on  the 
other  hand,  if  the  wheat  is  sown  after  the  rain  the  spores  in  the  soil 
have  had  time  to  germinate  and  become  exhausted  before  the  wheat 
germinates. 

In  order  to  determine  the  effect  of  the  time  of  sowing  on  the 
development  of  flag  smut  in  wheat  at  Granite  City,  Illinois,  seed  of  a 


WSS] 


FLAG  SMTTT  OF  WHEAT 


523 


large  number  of  varieties  was  smutted  with  spores  of  flag  smut  and 
sown  on  different  dates.  During  the  first  two  years  of  the  experiment 
all  these  varieties  behaved  relatively  in  about  the  same  way  so  that  in 
the  third  and  last  year  only  the  most  susceptible  variety,  Harvest 
Queen  (Red  Cross),  was  used.  The  effect  of  the  date  of  sowing  on  this 
variety  is  shown  in  Table  3. 

TABLE  3. — EFFECT  OF  DATE  OF  SOWING  ON  THE  SMUT  INFECTION  OF  HARVEST 
QUEEN  (RED  CROSS)  WHEAT,  A  HIGHLY  SUSCEPTIBLE  VARIETY 

Seed  inoculated  and  sown  in  experiment  plots  at  Granite  City,  Illinois. 


Date  of  sowing 

Percentage  of  infected  plants 

1920 

1921 

1922 

Average 
for  2  or  3 
years 

October,  4  to  12  

32.73 
15.50 

24.70 

27.20 
6.25 
5.29 
.55 
0.00 
0.00 

28.21 
10.87 
4.99 
.    .27 
0.00- 

October  15  to  20  

November  1  to  10  

4.70 

November  15  to  20  

0.00 

November  23  to  30  

0.00 

April  4  

Wheat  sown  early  in  October  smutted  more  than  wheat  sown  later 
in  the  fall.  There  was  little  difference,  however,  in  the  amount  of 
smut  in  sowings  made  sufficiently  early  to  insure  a  good  crop  of 
grain.  Sowings  made  after  the  first  of  November  showed  much  less 
smut  than  earlier  sowings.  Sowings  made  after  the  middle  of  No- 
vember were  smut-free,  but  the  yields  were  very  low.  Spring-sown 
smutty  seed  produced  a  smut-free  crop.  This  failure  of  wheat  sown 
in  late  fall  or  in  spring  to  become  infected  doubtless  is  due  largely 
to  the  fact  that  soil  temperatures  at  that  time  are  too  low  for  spore 
germination  and  infection.  Fields  of  spring  wheat  in  the  infested 
area,  other  than  the  experimental  plots,  were  examined  but  no  flag 
smut  was  found.  These  results  indicate  rather  decisively  that  tem- 
perature is  one  of  the  important  factors  in  spore  germination  and 
infection. 

VARIETAL  RESISTANCE 

The  discovery  of  varieties  of  wheat  which  are  desirable  com- 
mercially and  at  the  same  time  are  resistant  to  flag  smut  offers  the 
most  promising  means  of  controlling  the  disease.  McAlpine16  dis- 
cusses the  possibility  and  desirability  of  producing  resistant  varieties 
in  Australia.  Pridham20  found  considerable  varietal  differences  in 
the  field  infection  of  some  of  the  Australian  wheats.  He  did  not 
smut  the  seed  before  sowing,  however,  so  these  varieties  might  not 
have  been  equally  exposed  to  infection.  Brittlebank,1  in  1920,  sug- 
gested breeding  wheat  for  resistance  to  the  disease. 


524  BULLETIN  No.  242  [April, 

EXPERIMENTAL  WORK  TO  DETERMINE  VARIETIES 
COMPLETELY  RESISTANT 

In  the  fall  of  1919,  seed  of  several  varieties  of  wheat  was  thoroly 
smutted  with  spores  of  the  flag  smut  fungus  and  sown  in  the  infested 
area  at  Granite  City,  Illinois.  In  the  fall  of  1920  several  other  varie- 
ties were  added  to  the  list.  In  1921  those  varieties  which  had  shown 
more  than  3  percent  of  smut  were  dropped  from  the  list  and  only 
the  more  resistant  wheats  were  sown.  Among  these  varieties  which 
were  grown  two  or  three  years  several  remained  free  from  flag  smut 
even  tho  the  seed  was  heavily  smutted  before  sowing.  A  still  larger 
number  of  varieties  developed  less  than  1  percent  of  smut,  while  the 
remaining  varieties  were  more  or  less  susceptible.  The  seed  was  sown 
between  October  4  and  12  each  year. 

Table  4  contains  a  list  of  varieties  which  showed  no  infection  dur- 
ing two  or  three  years'  experiments.  For  the  present  purpose,  the 
varietal  names  under  which  the  various  samples  were  collected  have 
been  retained,  but  they  are  grouped  in  the  following  tables  under  varie- 
ties to  which,  upon  careful  examination,  they  were  found  properly  to 
belong. 

Hard  Red  Winter  Wheats. — Considering  first  the  hard  red  winter 
wheats  listed  in  Table  4,  it  should  be  stated  that  all  those  listed  are 
probably  about  equal  in  adaptation  for  growing  in  the  area  where 
flag  smut  is  found  in  Illinois,  altho  Kanred  probably  should  have 
preference  on  account  of  its  good  performance  in  Kansas  and  the 
availability  of  certified  seed.  From  the  farmer's  standpoint,  however, 
the  hard  red  wheats  are  not  fully  desirable.  This  class  of  wheat  is 
not  so  well  adapted  to  this  section  of  Illinois  as  are  the  soft  red  wheats. 
A  considerable  acreage  of  hard  red  winter  wheat  was  sown  by  farmers 
in  the  fall  of  1921  and  some  good  yields  were  reported  in  1922.  The 
season  favored  these  wheats  to  some  extent,  as  it  was  favorable  to 
severe  leaf  rust  development,  and  these  wheats  are  resistant  to  this 
rust.  It  is  reported,  however,  that  very  little  was  sown  in  the  fall 
of  1922.  The  lack  of  interest  in  these  wheats  probably  is  due  to  the 
presence  of  beards  and  to  their  weak  straw,  which,  in  wet  seasons, 
causes  lodging  on  low  land.  The  quality  of  grain,  also,  from  this 
class  of  wheat  is  not  of  the  best,  when  grown  on  wet  lowlands,  as 
there  is  a  tendency  toward  ' '  yellow  berry, ' '  which  is  undesirable  from 
the  market  standpoint.  For  the  reasons  stated  these  hard  red  wheats 
are  considered  undesirable  for  the  present  flag  smut  area  in  Illinois 
and  Missouri. 

Soft  Red  Winter  Wheats. — Varieties  of  soft  red  winter  wheats 
have  been  grown  almost  exclusively  by  farmers  in  the  flag  smut  sec- 
tion. All  those  listed  in  Table  4  probably  would  be  adapted  for 
growing  there,  with  the  certain  exception  of  Squarehead  Master  and 


10 23] 


FLAG  SMUT  OF  WHEAT 


525 


TABLE  4. — VARIETIES  OF  WHEAT  WHICH  REMAINED  FREE  FROM  FLAG  SMUT  WHEN 

GROWN  FROM  SMUTTED  SEED  FOR  Two  OR  THREE  YEARS  AT 

GRANITE  CITY,  ILLINOIS 

Seed  sown  between  October  4  and  12. 


Variety 

Source  or 
C.  I.  No.' 

Years  tested 

Hard  Red  Winter 
Kanred 
Kanred  

Kansas 

2 

Kanred  

Illinois 

2 

P-1068  

5880 

2 

Turkey 
Illinois  12-41  

Illinois 

2 

Soft  Red  Winter 
Beech  wood  

Missouri 

2 

Fulcaster 
Eversole  •  

3011 

2 

Marvelous  

Indiana 

2 

Stoner  

Virginia 

2 

Grandprize  (St.  Louis  Grandprize)  
Imperial  Amber  

5627 
3447 

3 
3 

Penquite  (Velvet  Chaff)  

3068 

2 

Red  May 
Early  Harvest  

4852 

2 

Red  Rock  

5597 

3 

Shepherd  

6163 

3 

Squarehead  Master  

3283 

3 

Ulta  No.  834"  

5747 

2 

•Seed  of  varieties  with  C.  I.  Nos.  was  furnished  by  the  Office  of  Cereal  In- 
vestigations. Where  a  state  is  given  as  the  source,  the  seed  was  obtained  from  the 
experiment  station  of  that  state,  with  the  exception  of  Marvelous,  the  seed  of 
which  was  obtained  from  a  farmer  in  Indiana. 

bThe  variety  recorded  here  as  Ulta  No.  834  is  beardless  with  red  glabrous 
chaff  and  red  kernels.  The  name  Ulta  is  usually  applied  to  a  variety  of  the 
Turkey  type. 

the  possible  exception  of  a  strain  known  as  Ulta  No.  834.  The  most 
desirable  varieties  from  the  local  farmer's  standpoint  are  Beechwood, 
Early  Harvest,  and  Shepherd,  as  they  are  beardless  and  produce  a 
good  quality  of  soft  red  grain.  They  also  yield  well  in  this  section 
of  the  country. 

Unfortunately,  there  is  no  commercial  supply  of  seed  of  the  three 
varieties  last  named.  *  Shepherd  is  being  increased  as  rapidly  as 
possible,  however,  from  nursery  stocks.  At  least  8  bushels  were 
grown  in  1922  on  a  farm  near  Granite  City,  Illinois,  and  this  seed 
was  sown  on  the  same  farm  in  the  fall  of  1922.  A  small  plot  of 
this  wheat  was  sown  also  on  another  farm  near  Edwardsville,  Illi- 
nois, and  an  increase  plot  was  sown  on  Arlington  Farm,  Rosslyn, 
Virginia,  from  nursery  supplies  available.  Shepherd  is  known  also 
to  be  immune  from  rosette  disease."  Up  to  the  present  time  the  seed 

•  The  information  given  here  and  in  the  following  pages  concerning  the  be- 
havior of  varieties  toward  the  rosette  disease  is  derived  from  unpublished  data 
furnished  by  H.  H.  McKinney  and  R.  W.  Webb  of  the  Office  of  Cereal  Investiga- 
tions, U.  S.  Department  of  Agriculture. 


526  BULLETIN  No.  242  [April, 

supplies  of  Early  Harvest  and  Beechwood  have  not  been  increased, 
altho  these  varieties  are  likely  to  be  satisfactory.  Early  Harvest 
has  been  immune  from  rosette  disease  in  experiments  in  this  locality; 
Beechwood  has  not  been  tested  in  the  experiments  with  rosette.  Ulta 
No.  834  represents  a  selection  concerning  which  little  is  known. 

Among  the  bearded  wheats  listed  in  Table  4,  Fulcaster  (Stoner  or 
Marvelous,  C.  I.  No.  2980)  should  probably  be  given  preference.  Seed 
of  this  variety  is  available  in  commercial  quantities  from  seedsmen  and 
farmers.  The  seed  of  Eed  Rock  also  is  available.  Large  stocks  are 
in  the  hands  of  farmers  in  Michigan  and  to  a  lesser  extent  of  farmers 
in  other  states  and  it  is  also  handled  by  seedsmen.  Eversole  and 
Imperial  Amber  probably  are  desirable  varieties  but  the  value  of 
Penquite  (Velvet  Chaff)  is  doubtful,  altho  none  of  these  three  have 
been  tested  for  yield  in  this  section.  All  the  above-named  bearded 
varieties  have  been  found  to  be  immune  from  the  rosette  disease  with 
the  exception  of  Imperial  Amber  and  Penquite  (Velvet  Chaff),  which 
have  not  been  tested. 

VARIETIES  APPARENTLY  HIGHLY  RESISTANT 

In  Table  5  are  listed  the  varieties  of  wheat  which  showed  less  than 
1  percent  of  smut  when  grown  from  smutted  seed  in  the  two  and  three 
years'  experiments.  Apparently  they  are  highly  resistant  to  flag 
smut.  The  small  percentage  of  infection  shown  may  represent,  in 
some  cases,  accidental  mixtures  in  the  stocks  used.  Several  excellent 
wheats  appear  in  this  list  and  of  some  of  them  commercial  seed  sup- 
plies are  available. 

One  group  of  bearded  wheats  with  glabrous  white  chaff,  purple 
straw,  and  red  kernels  embraces  a  number  of  varieties.  Bearded 
Purplestraw,  Dietz,  Fulcaster,  Lancaster,  Mammoth  Red,  Nigger,  and 
Stoner  are  practically  synonymous  names.  They  are  of  the  Fulcaster 
type.  The  high  resistance  of  these  strains,  coupled  with  the  fact 
that  Eversole  and  Stoner  (Marvelous)  are  found  in  Table  4,  among 
the  varieties  which  showed  no  infection,  indicates  that  this  variety 
group  is  at  least  highly  resistant  to  flag  smut.  Most  of  them  are 
also  immune  from  rosette  disease,  the  only  possible  exceptions  being 
Nigger  (C.  I.  No.  5689)  and  Bearded  Purplestraw,  which  have  not 
been  tested  for  rosette  resistance.  A  pure-line  strain  of  Nigger 
(C.I.  No.  5366),  however,  descended  from  a  single  plant  selection, 
is  very  susceptible  to  rosette. 

The  Fulcaster  variety  is  widely  grown  under  one  or  another  of 
its  names,  and  there  are  available  in  Illinois  and  Missouri  stocks  of 
pure  seed  practically  sufficient  to  sow  the  entire  flag  smut  area,  if 
such  a  course  were  necessary.  Some  of  these  commercial  stocks  are 


FIG.  3. — SPORES  OF  Urocystis  tritici  Kcke. 

A,  Photomicrograph    showing   the   spore    balls    as    they    appear    under   the 
microscope.     Magnified  approximately  230  diameters. 

B,  Drawing  showing  germinating  spores  of    Urocystis  tritici,   Kcke.     Note 
the   promycelium   bearing   two    or    three    secondary    spores,    or    sporidia,    at    the 
apex.     Magnified  approximately  460  diameters. 


19  25] 


FLAG  SMUT  OF  WHEAT 


529 


TABLE  5. — VARIETIES  OP  WHEAT  SHOWING  A  TRACE  OF  FLAG  SMUT  BUT 

AVERAGING  LESS  THAN   1    PERCENT   WHEN  GROWN  FROM  SMUTTY 

SEED  FOR  Two   OR  THREE   YEARS  IN  THE   EXPERIMENT 

PLOTS  AT  GRANITE  CITY,  ILLINOIS 


Variety 

Source  or 
C.  I.  No.' 

Years  tested 

Arcadian  (Early  Arcadian)  

3390 

3 

Beloglina  

.  5786 

2 

Brown  Fife  

1933 

2 

Flint 
Little  Red  

6349 

2 

Fulcaster 
Bearded  Purplestraw  

1911 

3 

Dietz  .  .  '  

Missouri 

2 

Dietz  

1981 

3 

Dietz  

3387 

2 

Fulcaster  

Tennessee 

2 

Fulcaster  

2 

Lancaster-Fulcaster  

1945 

3 

Stoner"  

2980 

3 

Genesee  Giant  

1744 

3 

Gipsy 
Gipsy  

5579 

3 

Gipsy  

3440 

2 

Reliable  

3508 

2 

Goens 
Miller's  Pride  

4865 

2 

Jones  Paris  Prize  

3568 

2 

Mammoth  Red  

2008 

3 

Mediterranean 
Mediterranean  

1395 

2 

Mediterranean  

3467 

2 

Missouri  Bluestem  

1912 

3 

Missouri  Bluestem  

1912-2 

3 

Nebraska  No.  28  

5147 

3 

New  Amber  Longberry  

1973 

3 

Nigger  

5689 

2 

P-1066  

5879 

2 

Penquite  (Velvet  Chaff)  

2 

Pesterboden 
Budapest  

5789 

3 

Poole  

3489 

3 

Red  May 
Michigan  Wonder  

5589 

3 

Red  Cross  

3579 

2 

Red  May  

5596 

2 

Red  Rockb  

5976 

3 

Rural  New  Yorker  No.  6.  .  .  .-  

3515 

3 

Turkey 
Malakof  5-460  

Illinois 

2 

Turkey  10-110    

Illinois 

2 

World's  Champion  

Illinois 

2 

Valley 
Valley...  

5658 

2 

Indiana  Swamp  

5969 

2 

Windsor  (Extra  Early  Windsor)  

3345 

3 

"Seed  of  varieties  with  C.  I.  Nos.  was  furnished  by  the  Office  of  Cereal  In- 
vestigations. Where  a  state  is  given  as  the  source,  the  seed  was  obtained  from  the 
experiment  station  of  that  state. 

bThe  slight  infection  of  this  lot  of  Stoner  and  of  Red  Rock  may  be  due  to 
accidental  mixture,  as  other  lots  of  these  varieties  and  of  Marvelous,  a  synonym 
of  Stoner,  are  found  in  the  immune  list  (Table  4). 


530  BULLETIN  No.  242  [April, 

being  tested  in  the  plots  sown  in  the  fall  of  1922,  and  data  will  be 
available  on  them  before  the  next  harvest.  Furthermore,  field  tests 
of  Fulcaster  wheat  made  in  southern  Illinois  show  it  to  be  one  of  the 
varieties  best  adapted  for  that  section.  It  is  also  an  excellent  milling 
wheat  for  bread  flour.  The  bearded  heads  probably  are  the  principal 
obstacle  to  its  adoption  by  farmers  in  this  section. 

Mammoth  Red  wheat  is  "grown  in  Maryland,  where  it  has  been 
distributed  by  the  Maryland  Agricultural  Experiment  Station  to 
farmers  of  that  state.  It  has  become  considerably  mixed,  however, 
and  the  pure  seed  stock,  so  far  as  known,  can  be  found  only  in  small 
quantities.  About  8  bushels  of  Mammoth  Red  were  produced  in  the 
flag  smut  area  this  year  from  seed  furnished  from  nursery  stocks 
by  the  U.  S.  Department  of  Agriculture,  and  this,  and  an  additional 
6  bushels  furnished  by  the  Maryland  Station,  was  sown  in  the  fall 
of  1922  in  this  area.  Another  small  plot  also  was  sown  in  this  area 
from  nursery  stocks.  With  proper  handling  there  should  be  sufficient 
seed  of  this  variety  for  extensive  sowings  in  a  few  years.  This  variety, 
like  others  in  this  group,  is  immune  from  rosette  disease. 

The  varieties  Gipsy,  Reliable,  and  Valley,  which  appear  in  Table  5, 
probably  are  well  adapted  to  the  area  in  question.  They  are  much 
like  the  Fulcaster  group  in  appearance,  but  do  not  have  purple  straw. 
They  are  important  wheats  in  some  sections  of  Ohio,  Illinois,  and 
Indiana.  Reliable  has  proved  immune  from  rosette,  but  the  other  two 
varieties  have  not  been  tested. 

A  group  of  bearded  wheats  having  glabrous  red  chaff  and  red 
kernels,  of  which  Mediterranean  is  the  principal  variety,  probably 
would  be  found  to  be  adapted  to  this  area.  Red  Rock  and  Miller's 
Pride  belong  to  this  group.  Miller's  Pride  is  highly  susceptible  to 
rosette  disease,  however,  while  Mediterranean  is  slightly  susceptible. 
Red  Rock  appears  to  be  immune. 

The  Red  May  group  of  beardless  wheats  with  glabrous  red  chaff 
and  red  kernels  shown  in  Table  5  includes  Michigan  Wonder,  Red 
Cross  (C.  I.  No.  3579),  and  Red  May.  They  are  similar  in  appear- 
ance to  Shepherd  and  other  varieties  listed  in  Table  1.  They  would 
be  adapted  to  the  flag  smut  section  and  appear  to  be  immune  from 
rosette  disease.  Poole  (C.  I.  No.  3489)  is  similar  in  appearance  and 
adaptation  to  this  group  but  it  has  not  been  tested  in  rosette 
experiments. 

Other  varieties  appearing  in  Table  5  are  either  hard  red  winter 
wheats  or  are  of  other  types  not  considered  desirable  for  growing  in 
this  area. 

WHEAT  VARIETIES  GENERALLY  GROWN  IN  THE  FLAG  SMUT  AREA 

Wheat  is  grown  very  intensively  in  Madison  and  St.  Clair  coun- 
ties. In  1919  (Census  data)  wheat  occupied  38.2  percent  of  the  im- 


19*3] 


FLAG  SMUT  OP  WHEAT 


531 


proved  land  on  the  farms  of  Madison  county  and  41.7  percent  in  St. 
Clair  county.  Of  the  acreage  of  all  land  in  crops,  wheat  occupied 
45  and  47  percent,  respectively,  in  these  two  counties.  This  must 
mean  that  wheat  frequently  follows  wheat  in  the  rotation  and  that 
wheat  fields  are  practically  contiguous  or  only  slightly  separated  one 
from  another  over  almost  the  entire  area.  Both  these  conditions  favor 
the  development  and  spread  of  flag  smut  and  other  diseases  and  also 
lead  to  their  accumulation  in  the  soil.  Inasmuch  as  wheat  is  such 
an  important  crop  in  this  area,  it  is  not  practicable  to  discontinue 
growing  it  in  order  to  combat  the  disease. 

In  Table  6  are  given  the  results  of  an  experiment  to  determine 
the  susceptibility  of  the  principal  soft  red  winter  varieties  now  grown 
by  farmers  in  the  flag  smut  area.  All  of  them  were  found  to  be  more 
or  less  susceptible  to  the  disease.  Harvest  Queen  (Red  Cross  or 
Salzer's  Prizetaker),  which  is  most  suspectible,  fortunately  has  al- 

TABLE  6. — WHEAT  VARIETIES  GROWN  COMMERCIALLY  IN  THE  INFESTED  AREA, 
ALL  OP  WHICH  ARE  SUSCEPTIBLE  TO  FLAG  SMUT  AND  SHOULD  NOT 
BE  SOWN  IN  THIS  AREA 


Variety 

Number  of  selections 

Average 
percentage 
of  smut 

Number 
of  years 
tested 

Flint  (May)  

Average  of  two  selections.  .  .  . 

20  4 

1 

Fultz  

Average  of  several  selections  . 

9.5 

2 

Harvest  Queen  (Salzer's 
Prizetaker  or  Red 
Cross)  

Average  of  several  selections 

23  77 

3 

Jones  Fife  

Average  of  two  selections  .... 

6.97 

2 

Red  Wave  

Averace  of  several  selections  . 

4.27 

2 

most  disappeared  from  the  worst  infested  section,  since  the  farmers 
have  seen  how  heavily  it  smuts.  Red  Wave  and  Fultz  are  still  widely 
grown. 

The  use  of  resistant  varieties,  especially  those  varieties  that  have 
shown  immunity  in  the  flag  smut  experiments,  offers  the  most  effective 
means  of  control.  It  is  possible  that  by  the  use  of  these  varieties, 
kept  pure  and  free  of  susceptible  mixtures,  the  disease  may  be  en- 
tirely eradicated. 


INDEX   OF   ALL   WHEAT   VARIETIES   TESTED    SHOWING 
RESISTANCE  AND  SUSCEPTIBILITY  TO  FLAG  SMUT 

All  varieties  of  wheat  which  have  been  grown  in  these  experiments 
on  resistance  to  flag  smut  are  listed  in  Table  7,  with  a  record  of  the 
annual  infection  and  the  average  infection  for  the  two  or  the  three 
years  during  which  they  were  tested.  This  table  contains  not  only 
all  the  varieties  recorded  in  the  preceding  tables,  but  many  susceptible 
varieties  not  presented  before. 


532 


BULLETIN  No.  242 


[April, 


TABLE  7. — COMPLETE  LIST  OP  WHEAT,  SPELT,  AND  EMMER  VARIETIES  GROWN 

FROM  SEED  INFESTED  WITH  FLAG  SMUT,  SHOWING   HEAD  AND  KERNEL 

CHARACTERS  AND  SUSCEPTIBILITY  TO  SMUT:     EXPERIMENT  PLOTS 

AT  GRANITE  CITY,  ILLINOIS,  1920-1922 


Crop  and  variety 

Source  or 
C.  I.  No.* 

Description 

Percentage  of  infected  plants 

Headb 

Ker- 
nel0 

1920 

1921 

1922 

Average 
for  2  or  3 
years 

WHEAT 
Acme  

3115-2 
4848 
3390 
1942 
Missouri 
Illinois 
1933 

180 
180 
5342 

5955 
2906 
3326 
3484 

3614 
6161 

Illinois 
3384 

3396 
3608 

Granite 
City 
6349 
Granite 
City 
Granite 
City 
Granite 
City 
Granite 
City 
Granite 
City 

BRG 
ARG 
ARG 
BWV 
ARG 
BWG 
ARV 

ARG 
ARG 
ARG 

AWG 
ARG 
ARG 
ARG 

BRG 
ARG 

ARG 
BWG 

BRG 
BWG 

AWG 
AWG 

AWG 
AWG 
AWG 
AWG 
AWG 

SR 
SR 
W 
SW 
SR 
HR 
SR 

SR 
SR 
SR 

SR 

SR 
SR 
SR 

SR 
W 

W 
W 

SR 
SR 

SR 
SR 

SR 
SR 
SR 
SR 
SR 

1.6 

trace 

14.6 
1.4 
0.0 
9  2 

'4'9 
0.0 

8.10 
3.15 
trace 

Ahrens  

Arcadian  (Early  Arcadian) 
Bearded  Winter  Fife  .... 
Beech  wood  

'".3 

trace 
5.0 

11.1 

0.0 
2.2 
0.0 

3.2 

0.0 
2.0 

0.00 
2.10 
.15 

1.60 

Beloglina  

Brown  Fife  

China 
China  

China  (Seed  from  Tenn.) 
Pennsylvania  Bluestem. 
Climax 
K.  B.  No.  2  

.9 

2.5 
1  4 

4.7 

2.80 
6.80 

Currell  (Currell's  Prolific)  . 
Currell  (Currell's  Prolific)  . 
Currell  (Pearl  Prolific)  .... 
Currell  X  Diehl-Mediter- 
ranean 

1.4 

4.0 

3  7 

2.70 

0.0 
3.5 

0.0 
6.6 
.4 

Dawson  (Dawson's  Golden 
Chaff)  

8.1 

17.5 
12.5 

7.3 

5.80 

6.25 
6.95 

Dawson  (Dawson's  Golden 
Chaff)  

Democrat  

Diehl-Mediterranean 
Eclipse  

Diehl-Mediterranean  X 
Jones  Fife   .            ... 

Flint 
Indiana  May  

13.4 
0.0 

24  0 

"  .7 

'!35 

Little  Red  

May  

May  

16.8 
16.5 
11.9 
13.7 

;::: 



Red  May  

Red  May  

Red  May  

"Seed  of  varieties  with  C.  I.  Nos.  was  furnished  by  the  Office  of  Cereal  In- 
vestigations. Where  a  state  is  given  as  the  source,  the  seed  was  obtained  from 
the  experiment  station  of  that  state,  with  the  exception  of  ten  lots  from  Indiana, 
as  follows,  which  were  obtained  from  farmers:  Burbank  Super,  Harvest  King 
(two  lots),  Marvelous,  Michigan  Amber,  New  York  No.  10,  Poole,  Red  Chaff, 
Red  Wave,  and  Rudy.  Varieties  with  Granite  City  given  as  a  source  were  col- 
lected from  farmers  in  the  vicinity  of  that  city  in  Illinois. 


b  A  =  awnless 
B  —  bearded 

W  =  white  or  yellow  chaff 
B  =  red  or  brown  chaff 
Bl  =  black  chaff 

Q  =  glabrous  chaff   (not  velvety) 
V  =  velvet  or  pubescent  chaff 


c  R  =  red 
W  —  white 
H  =  hard 
S  -  soft 


198S] 


FLAG  SMUT  OF  WHEAT 


533 


TABLE  7. — Continued 


Crop  and  variety 

Source  or 
C.  I.  No. 

Description 

Percentage  of  infected  plants 

Head 

Ker- 
nel 

1920 

1921 

1922 

Average 
for  2  or  3 
years 

Red  May  

Granite 
City 

1911 
1911-1 
1981 
Missouri 
3387 

1981 
3011 
Missouri 
3013 
Tennessee 
6162 

AWG 

BWG 
BWG 
BWG 
BWG 
BWG 

BWG 
BWG 
BWG 
BWG 
BWG 
BWG 
BWG 
BWG 
BWG 
BWG 
BWG 
BWG 

AWG 
AWG 
AWG 
AWG 
AWG 
AWG 
AWG 
AWG 

BRG 

BWG 
BWG 
BWG 
BWG 
BWG 
BWG 
BWG 
BWG 
BWG 
BWG 

BRG 
BRG 

BRG 
ARV 

AWG 
AWG 
AWG 

AWG 

SR 

SR 
SR 
SR 
SR 
SR 

SR 
SR 
SR 
SR 
SR 
SR 
SR 
SR 
SR 
SR 
SR 
SR 

SR 
SR 
SR 
SR 
SR 
SR 
SR 
SR 

W 

SR 
SR 
SR 

SR 
SR 
SR 
SR 
SR 
SR 
SR 

SR 
SR 

SR 
SR 

SR 
SR 
SR 

SR 

14.2 

Fulcaster 
Bearded  Purplestraw.  .  . 
Bearded  Purplestraw.  .  . 
Dietz  .  .  .  .  •  

trace 
.9 
trace 

0.0 

1.6 
2.2 
2.5 
1.0 
1.4 

1.1 
0.0 
0.0 
0.0 
0.0 

.90 
1.03 
.83 
.50 
.70 

Dietz  

•  Dietz  

Dietz  (Seed  from 
Tennessee)  

Eversole  

0.0 
2.1 

8.2 

0.0 
1.2 

0.00 
1.65 

Fulcaster  

Fulcaster  

Fulcaster  

trace 
0.0 

1.0 
3.6 

.8 
3  7 

'6!6 

.5 

.50 
1.20 
.65 

Fulcaster  

Fulcaster  

Fulcaster  

4862 
1945 
Indiana 
2980 
Virginia 

1923 
3598 
3604 
Missouri 
3349 
3423 
3594 
5643 

1744 

Missouri 
5579 
3440 
Illinois 
3439 
Missouri 
5307 
3508 
Illinois 
-5613 

3428 
4865 
Indiana 
6684 

5627 

Missouri 
4882 
5957 
Granite 
Citv 

Lancaster-Fulcaster  
Marvelous  

trace 
".'4 

.8 
3.3 

0.0 
0.0 
.5 
0.0 

11.45 
1.6 
4  0 

1.5 

0.0 
.7 
0.0 

.50 
0.00 
.53 
0.00 

6.12 
2.45 

Stoner  

Stoner  

Fultz 
Fultz  

Fultz  

Fultz  

Fultz  

23  3 

Fultz  

7  9 

Fultz  

13  7 

Fultz  

10.0 

Fultzo-Mediterranean  .... 
Genesee  Giant  (Early 
Genesee  Giant)  

0.0 
trace 

3.7 
0.0 
3  4 

1.0 

1.85 
.35 

Gipsy 
Defiance  

Gipsy  

1.3 

0.0 
0.0 
4  1 

.8 
1.7 

.70 
.85 

Gipsy.  • 

/-<• 
Uipsv  .... 

Gipsy  

4  2 

Lebanon  

0.0 

26  8 

4.1 

2.05 

Niagara  >  . 

Reliable  

0.0 

8.5 

.3 

.15 

Gladden  

Gluten  

1  0 

Goens 
Goens  

1.3 

3.8 
1.5 
13  3 

6.6 

2.55 
.75 

Miller's  Pride  

Red  Chaff  

Golden  Wave  

1  8 

« 

Grandprize  (St.  Louis 
Grandprize)  

0.0 

0.0 

28  3 

0.0 

0.00 

Harvest  Queen 
Harvest  Queen  

Harvest  Queen  

12  6 

Red  Cross  

27.0 

23.3 
30.7 

24.5 

24.93 

Red  Cross  

534 


BULLETIN  No.  242 


[April, 


TABLE  7. — Continued 


Crop  and  variety 

Source  or 
C.  I.  No. 

Description 

Percentage  of  infected  plants 

Head 

Ker- 
nel 

1920 

1921 

1922 

Average 
for  2  or  3 
years 

Red  Cross  

Illinois 
Granite 
City 
Granite 
City 
Illinois 
4843 

5406 
Illinois 
3447 
4834 

Indiana 
Granite 
City 
Granite 
City 
Granite 
City 
5608 
3610 
3568 

5146 
5591 
Illinois 
Kansas 
2401 
5592 
Granite 
City 
4823 
5584 
3472 
5823 

3355 
2008 
1974 
Washing- 
ton 1092 

5824 
Missouri 
3563 
3565 
5404 

Missouri 
1395 
3467 
Illinois 
1912 
1930 

AWG 
AWG 

AWG 
BWG 
BWG 

ARG 
ARG 
BRG 
BRG 

AWV 
AWV 
AWV 

AWV 
AWV 
ARG 
ARG 

BWG 
BWG 
BWG 

BWG 
BWG 

AWG 
AWG 
BRG 
BRG 

BWG 
BWG 
AWG 

AWG 

AWV 
AWV 
AWV 
AWV 
AWV 

BRG 
BRG 
BRG 
BRG 
BRG 
BRG 

SR 
SR 

SR 
R 
R 

SR 
SR 
SR 
SR 

SR 
SR 
SR 

SR 
SR 
SR 
W 

HR 
HR 
HR 

HR 
HR 

SR 
SR 
SR 
SR 

W 
SR 
W 

W 

SR 
SR 
SR 
SR 
SR 

SR 
SR 
SR 
SR 
SR 
SR 

24.7 
14  1 

27.2 

25.95 

Salzer's  Prizetaker  
Salzer's  Prizetaker  

Hussar  (Red  Hussar)  
Hussar  (Red  Hussar)  
Illini  Chief 
Illini  Chief  

18.1 

3.0 

0.0 

.3 

5.7 
7  2 

3.00 

Illini  Chief  

Imperial  Amber  

0.0 

0.0 
3.2 

0.0 

0.00 

Indiana  Swamp  Selection  . 
Jones  Fife 
Burbank  Super  

10  8 

Jones  Fife  

7.2 

Jones  Fife  

5  7 

Jones  Fife  

7.6 

Jones  Fife  

4.3 

2.7 

trace 

5.2 

4.75 

Jones  Fife  X  Dawson  .... 
Jones  Paris  Prize  

0.0 

0.0 

1  7 

1.1 

7.4 

.55 
2.46 

Kanred 
Xanred  

Kanred  

Kanred  

0.0 

0.0 
4.0 

0.0 
0.0 

0.00 
0.00 

Kanred  

Kanred  

King  Harvester  

15  9 

Leap  (Leap's  Prolific)  .... 
Leap  (Leap's  Prolific)  .... 
Link  (Missing  Link)  

.7 
0.0 
2.3 

0.0 
0.0 
0.0 

6.9 

3.80 

0.0 
1.6 

0.0 
0.0 

4.6 

.8 

4.6 

.8 

2.30 
1.20 

1.53 
.26 

Longberry  No.  1  

Mammoth  Amber  (mixed 
in  1922)  

Mammoth  Red  

Martin  (Martin  Amber)  .  . 
Martin  (Martin  Amber)  .  . 

Mealy 
Mealy  

0  0 

7.1 

7.5 
6.4 

7.30 

Mealy  

Mealy  

12  1 

Mealy  

15.8 

Mealy  

4  9 

M  editerranean 
Mediterranean  

1.8 
0.0 
0.0 
3  6 

1.4 
.7 
.3 

1.6 
.35 
.15 

Mediterranean    

Mediterranean  

Mediterranean          .    . 

Missouri  Bluestem  

0.0 

8.2 

2.5 

7.2 

.3 

.90 

7.70 

Rockv  Mountain  .  . 

1923} 


FLAG  SMUT  OP  WHEAT 


535 


TABLE  7. — Continued 


Crop  and  variety 

Source  or 
C.  I.  No. 

Description 

Percentage  of  infected  plants 

Head 

Ker- 
nel 

1920 

1921 

1922 

Average 
for  2  or  3 
years 

Missouri  Bluestem 
(Selection)  

1912-2 
5147 

1973 
3361 
Indiana 
5689 
3481 
5879 
5880 

5629 
3068 

5789 
Illinois 
Illinois 

Missouri 
Indiana 
Indiana 
Granite 
City 
Granite 
City 
4859 
1979 
3489 
Tennessee 
Indiana 
1733 
5370 

3339 

5638 
4871 

1915 
-1957 

5640 

4852 
Missouri 
5319 
3399 
Indiana 
Illinois 
5589 
4868 
3492 
3579 
5596 

BWG- 
BWG 

BRG 
BRG 

BWG 
BWG 
BWG 
BWG 

BRV 
BRV 
BRV 

BWG 
BWG 
BWG 

ARG 
ARG 
ARG 

ARG 

ARG 
ARG 
ARG 
ARG 
ARG 
ARG 
ARG 
ARG 

AWG 

AWG 
AWG 

AWG 
AWG 

ARG 

ARG 
ARG 
ARG 
ARG 
ARG 
ARG 
ARG 
ARG 
ARG 
ARG 
ARG 

SR 
R 

W 
W 

SR 
.   W 
HR 
HR 

SR 
SR 
SR 

HR 
HR 
HR 

SR 
SR 
SR 

SR 

SR 
SR 
SR 
SR 
SR 
SR 
SR 
SR 

SR 

SR 
SR 

SR 

SR 

SR 

SR 
SR 
SR 
SR 
SR 
SR 
SR 
SR 
SR 
SR 
SR 

0.0 
.3 

trace 

0.0 
1.2 

.8 
4  6 

.3 
.3 

0.0 

.10 
.60 

.26 

Nebraska  No.  28  

New  Amber  Longberry 
New  Amber.  Longberry  . 
New  Amber  Longberry  . 
New  York  No.  10  

5.8 

Nigger  

'6^6 

1.4 

8.8 
.5 
0.0 

0  8 

0.0 

'6!6 

0.0 

.70 
4.40 
.25 
0.00 

Oatka  Chief  

P-1066  

P-1068  

Penquite  (Velvet  Chaff) 
Velvet  Chaff  

Velvet  Chaff  

0.0 

0.0 
0.0 

0.0 
2.7 
5  8 

1.0 
0.0 

.3 
3.1 

.50 

0.00 

.10 
2.90 

Velvet  Chaff  

Pesterboden 
Budapest  

Hungarian  

Pesterboden  .  . 

Poole  

2.0 

Harvest  King  

Harvest  King  .... 

0  0 

Harvest  King   . 

4  1 

Harvest  King  

8.8 

Harvest  King  

17  6 

Hedge  Prolific.  . 

4  3 

Poole  

.6 
trace 
0.0 

1.8 
0.0 
2.6 
3  1 

2.6 
0.0 

5.8 

1.66 
trace 
2.80 

Poole  

Poole  

Poole  

Poole  Type  (Selection)  .  . 
Portage  

2.4 

4.1 
6  3 

3.25 

Prosperity  (American 
Bronze)  

0.0 

Prosperity  (American 
Bronze)  

6.5 

Purdue  No.  1  

7.2 
3.2 

0.0 

12.1 
9.6 

10  4 

6.0 

3.00 

9.65 
6.45 

Purplestraw 
Purplestraw  

Purplestraw  

Red  Clawson 
Early  Red  Clawson  .... 
Red  May 
Early  Harvest  

0.0 
1  3 

0.0 

0.00 

Early  Ripe  

Early  Ripe  

2  5 

Enterprise  

7  1 

Michigan  Amber  

2  9 

Michigan  Amber  

9 

Michigan  Wonder  

1.2 

.9 
2.5 
7  0 

0.0 
0.0 

.70 
1.25 

Orange  

Pride  of  Indiana  .  . 

Red  Cross  

'o.'o 

0.0 
1.9 

1.8 

.90 
.95 

Red  Mav.  . 

536 


BULLETIN  No.  242 


[April, 


TABLE  7. — Continued 


Crop  and  variety 

Source  or 
C.  I.  No. 

Description 

Percentage  of  infected  plants 

Head 

Ker- 
nel 

1920 

1921 

1922 

Average 
for  2  or  3 
years 

Red  Rock 
Red  Rock  

5976 
5597 

Illinois 

5582 
Indiana 
Illinois 
Granite 
City 
Granite 
City 
Granite 
City 
5693 

5599 
Indiana 
5343 

3515 
5736 
5737 
6163 
3283 
Granite 
City 
3527 

Illinois 
Illinois 
Illinois 
Illinois 
5603 
Illinois 
Illinois 
Illinois 
Illinois 
Illinois 
5747 

5969 
Illinois 

5658 
4846 
3135 

3345 

4878 
Tennessee 

5696 
2907 

BRG 
BRG 
/BRG 
\BWG 

ARG 
ARG 
•ARG 

ARG 
ARG 

ARG 
ARG 

BWG 
BWG 
ARG 

ARG 
ARG 
ARG 
ARG 
ARG 

BWG 

BWG 
BWG 
BWG 
BWG 
BWG 
BWG 
BWG 
AWG 
BWG 
BWG 
ARG 

BWG 
/BWG 

\BRG 

BWG 
ARG 
BWG 

ARG 
ARG 

AWG 
AWG 

SR 
SR 

SR 

SR 
SR 
SR 

SR 

SR 

SR 
SR 

SR 
SR 
SR 

SR 
SR 
SR 
SR 
SR 

SR 

HR 
HR 
HR 
HR 
HR 
HR 
HR 
R 
HR 
HR 
SR 

SR 
SR 

SR 
SR 
SR 

W 

SR 

SR 
SR 

trace 
0.0 

0.0 
0.0 

3  7 

.7 
0.0 

.23 
0.00 

Red  Rock  

Red  Rock  (mixed)  

Red  Wave 
Red  Wave  

trace 

Red  Wave  

5.2 
4.0 

3  3 

1.1 

2.8 

3.15 
3.40 

Red  Wave  :  

Red  Wave  

Red  Wave  

4  8 

Red  Wave  

.  ' 

6.7 

Rochester  (Rochester  Red) 
Rudy 
Rudy  

10  1 

2  3 

Rudy  

1.3 

Rupert  (Rupert's  Giant)  . 
Rural  New  Yorker  No.  6 
Rural  New  Yorker  No.  6 
Rural  New  Yorker  No.  6 
Russian  

2.7 
trace 

4.0 

0.0 

8  1 

2.6 

3.35 
0.86 

1  3 

Shepherd  

0.0 
0.0 

0.0 
0.0 

18  0 

0.0 
0.0 

0.00 
0.00 

Squarehead  Master  

Texas  Red  

Treadwell  

trace 

0.0 

.5 
0.0 
.4 
3  5 

8.2 

0.0 
0.0 
0.0 

2.75 

.25 
0.00 
.20 

Turkey 
Illinois  10-110  

Illinois  12-41  

Malakof  No.  5-460.  .    .  . 

Minnesota  Reliable  .... 
Turkey 

0  0 

Turkey  

0.0 

2.0 
2.3 
2.3 
2.7 
1.3 
0.0 

1.6 

5  8 

.3 
1.5 
1.5 
1.4 

.4 
0.0 

1.15 
1.90 
1.90 
2.05 

.85 
0.00 

.80 

Turkey  Hybrid  No.  402 
Turkey  Hybrid  No.  509 
Turkey  Hybrid  No.  514 
World's  Champion  

Ulta  No.  834  

Valley 
Indiana  Swamp  

Indiana  Swamp  (mixed) 
Valley  

0  0 

1.8 

.6 

.30 

Wheedling  

White  Bearded  

2  9 

Windsor 
Extra  Early  Windsor.  .  . 
Winter  Chief  

trace 

6!6 

0.0 
0.0 
3.4 

6.6 
21.2 

0.0 
2.9 

trace 
1.45 
1.70 

Woods  

Wyandotte 
Wyandotte  Red  

Zimmerman  .  . 

WSS] 


FLAG  SMUT  OP  WHEAT 
TABLE  7. — Concluded 


537 


Crop  and  variety 

Source  or 
C.  I.  No. 

Description 

Percentage  of  infected  plants 

Head 

Ker- 
nel 

192,1 

1921 

1922 

Average 
for  2  or  3 

years 

SPELT 
Alstroum  

1773 
1724 
1772 

AWG 
BWG 
ARG 

SR 
SR 
SR 

0.0 
0.0 
0.0 

0.0 
0.0 
0.0 

0.00 
0.00 
0.00 

Bearded  Winter  

Red  Winter  

EMMER 
Black  Winter  

2337 

BB1V 

R 

.... 

0.0 

0.0 

0.00 

CONCLUSIONS 

Flag  smut  can  be  controlled  by  treatment  of  the  seed  with  copper 
sulfate  and  lime  or  with  copper  carbonate,  if  the  spores  are  carried 
only  on  the  seed. 

Control  by  seed  treatment  cannot  be  depended  on  where  spores 
are  present  in  the  soil.  To  be  effective  under  these  conditions  the 
fungicide  would  necessarily  have  to  remain  active  until  the  seed  had 
germinated,  for  it  is  at  the  time  of  germination  that  infection  from 
the  spores  in  the  soil  takes  place.  However,  even  tho  the  disinfectant 
should  remain  active  until  that  time,  there  might  be  infection  from 
the  spores  in  the  soil  that  were  near  enough  the  young  plant  to  in- 
fect it  but  too  far  from  the  seed  to  be  destroyed  by  the  disinfectant. 

The  use  of  other  crops  following  wheat  and  the  careful  disinfec- 
tion of  threshing  machines,  wagon  beds,  bins,  etc.,  which  may  have 
been  contaminated  tends  to  reduce  the  amount  of  infection. 

Time  of  planting  is  one  of  the  important  factors  in  spore  germi- 
nation and  infection.  Unfortunately,  however,  when  wheat  is  sown 
late  enough  in  the  fall  to  escape  infection,  the  risk  of  loss  in  produc- 
tion is  too  great  to  make  this  a  practical  means  of  control. 

The  discovery  of  varieties  of  wheat  which  are  desirable  commer- 
cially and  at  the  same  time  are  resistant  to  flag  smut  offers  the  most 
promising  means  of  controlling  the  disease.  The  results  of  experi- 
ments so  far  conducted  show  fourteen  varieties  or  strains  to  be 
immune  and  forty-one  others  to  be  highly  resistant.  If  wheat  grow- 
ing were  discontinued  for  a  number  of  years  thruout  the  infested  area 
and  all  volunteer  wheat  were  destroyed  the  disease  might  be  eradicated, 
but  even  this  is  not  certain.  The  ultimate  solution  probably  will  be 
the  using  of  resistant  varieties. 


538  BULLETIN  No.  242 

LITERATURE  CITED 

1.  BRITTLEBANK,  C.  C.     Flag  smut.    Jour.  Dept.  Agr.  Victoria,  18,  4,  240-243. 
April,  1920. 

2.  BRITTLEBANK,  C.  C.     Seed-borne  diseases,  "take-all  and  flag  smut."    Jour. 
Dept.  Agr.  Victoria,  19,  7,  447.     July,  1921. 

3.  COBB,  N.  A.    Smut.    Agr.  Gaz.  N.  S.  Wales,  2,  672.    1891. 

4.  DARNELL-SMITH,  G.  P.    Flag  smut  of  wheat.    Agr.  Gaz.  N.  S.  Wales,  25,  4, 
285-287.     April,  1914. 

5.  DAKNELL-SMITH,  G.  P.,  and  Eoss,  H.    A  dry  method  of  treating  seed  wheat 
for  bunt.    Agr.  Gaz.  N.  S.  Wales,  30,  10,  685.    October,  1919. 

6.  DARNELL-SMITH,  G.  P.,  and  Eoss,  H.     Fungicidal  dusts  for  the  control  of 
smut.    Agr.  Gaz.  N.  S.  Wales,  32,  796-798.     1921. 

7.  DARNELL-SMITH^   G.   P.,   and   MACKINNON,  E.     Fungus   diseases   of  wheat. 
Dept.  Agr.  N.  S.  Wales,  Farmers'  Bui.  102,  14-19.     1915. 

8.  GLENN,  P.  A.,  et  al.     Flag  smut  of  wheat.     111.  Dept.  Agr.  Circ.  4.     1922. 

9.  HAMBLIN,  C.  O.     Flag  smut  and  its  control.    Agr.  Gaz.  N.  S.  Wales,  32,  23. 
1921. 

10.  HEALD,  F.  D.,  and  SMITH,  L.  J.     The  dusting  of  wheat  for  bunt  or  stinking 
smut.    Wash.  Agr.  Exp.  Sta.  Bui.  168.    June,  1922. 

11.  HORI,  S.     Seed  infection  by  smut  fungi  of  cereals.     Bui.  Imp.  Cent.  Agr. 
Exp.  Sta.  Japan,  1,  2,  171-172.     1907. 

12.  HUMPHREY,  HARRY  B.,  and  JOHNSON,  AARON  G.    Take-all  and  flag  smut,  two 
wheat  diseases  new  to  the  United  States.     U.  S.  D.  A.  Farmers'  Bui.  1063. 
1919. 

13.  KORNICKE,  F.     Mykologische  Beitrage.     Hedwigia,  16,  33-34.     1877. 

14.  KUEIIN,  J.    Mittheilungen  iiber  die  Entwickelungsformen  des  Getreidebrandes 
und  die  art  des  Eindringens  der  Keimfaden  in  die  Wahrpflanze.     Bot.  Zeit., 
32,  122.     1874. 

15.  McALPiNE,  D.     Flag  smut  of  wheat.     Jour.  Dept.  Agr.  Victoria,  3,  168-169. 
1905. 

16.  MCALPINE,  D.    The  smuts  of  Australia,  88-102.    1910. 

17.  M^CKIE,  W.  W.     Quarantine  against  "flag  smut"   and  "take-all."     Mo. 
Bui.  Dept.  Agr.  Calif.,  8,  8,  456-460.     1919. 

18.  MACKIE,  W.  W.,  and  BRIGGS,  F.   N.     Fungicidal  dusts  for  the  control  of 
smuts.     Science,  n.  s.,  52,  540.     1921. 

19.  PEACOCK,  E.  M.     Field  experiments  with  flag  smut.    Agr.  Gaz.  N.  S.  Wales, 
24,  381-384.     1913. 

20.  PRIDHAM,  J.  T.    Flag  smut  of  wheat.    Agr.  Gaz.  N.  S.  Wales,  24,  25-26.   1913. 

21.  PUTTERILL,  V.  A.     Flag  smut  of  wheat.    Jour.  Dept.  Agr.  Union  So.  Africa, 
1,  252-257.     1920. 

22.  EEED,  GEORGE  M.,  and  DUNGAN,  GEORGE  H.    Flag  smut  and  take-all.    111.  Agr. 
Exp.  Sta.  Circ.  242.     1920. 

23.  SYDOW,  H.  et  P.,  and  BUTLER,  E.  J.    Fungi  Indiae  orientalis.     Ann.  Mycol., 
4,  427.     1906. 

24.  TISDALE,  W.  H.,  and  GRIFFITHS,  MARION  A.     Flag  smut  of  wheat  and  its 
control.    U.  S.  D.  A.  Farmers'  Bui.  1213.    1921. 

25.  WOLFF,  E.    Der  Brand  des  Getreides,  16-17.    Halle,  1873. 

Papers  ivhich  have  appeared  since  the  preparation  of  this  manuscript : 

26.  MIYAKE,'  I.     Studies  in  Chinese  fungi.     Bot.  Mag.  Tokyo,  26,  303,  51-66. 
1912.     Unpublished  translation  by  W.   T.  Swingle,  1923. 

27.  NOBLE,  E.  J.     Studies  on  Urocystis  tritici  Koern.,  the  organism  causing  flag 
smut  of  wheat.     Phytopath.,  13,  3.     March,  1923. 


UNIVERSITY  OF  ILLINOIS-URBANA 


